CVE-2026-87929EPSS p42.7%
CVE-2026-87929CVE-2026-87929
Description
MaxSite CMS through 109.6 ships with a hardcoded session encryption key in application/config/config.php that is never changed during installation, allowing unauthenticated attackers to forge administrator session cookies. Attackers can mint a malicious ci_session cookie with administrator privileges by computing an HMAC-SHA1 using the publicly known encryption key, bypassing authentication checks in is_login() and mso_check_allow() functions.
Scoring
| CVSS | 9.8 () |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 0.53% probability of exploitation · percentile 42.7% · 2026-10-05T12:00:23Z |
| Last modified | 2026-09-14 |